This is a national application based upon International Application No. PCT/ES00/00499, which was filed on Dec. 29, 2000 and which published in Spanish on Jul. 12, 2001, which in turn claims priority from Spanish Application No. U 200000004, which was filed on Jan. 3, 2001, and Spanish Application No. P200002360 filed on Sep. 29, 2000.
The present invention relates to a device that is to constitute the means for transmission of a dose of semen from a recipient container to the uterus of a female pig, for the post-cervical artificial insemination thereof.
The object of the invention is to achieve a device with some optimum features, that not only facilitates the anatomic implantation thereof in the pig, prior to the insemination itself, but also determines some optimum results in said insemination, with a minimal consumption of semen, or what constitutes an optimum use of the sperm introduced by means of the device and the deposition in the uterine horn of the female pig herself, by means of outlets with which for such purposes the expulsion end of the device has been equipped.
The application of the seminal dose in pigs on heat is performed normally by the vaginal route, using an instrument known as a catheter, this being made from a tubular implement, although it can present different forms. In all cases, it serves to reach the neck of the uterus and attach itself in the first 3-4 centimetres, as a nut does on a bolt, allowing the seminal dose to be applied through it, which has to pass through the rest of the uterine neck, approximately another 15 centimetres, before reaching the neck of the uterus.
There are currently different types of catheter that range from the classical reusable xe2x80x9cMelrosexe2x80x9d type made form a single rubber or similar piece that is very similar to the penis of the male pig, to an almost endless list of disposable plastic catheters.
These latter are generally formed of three pieces that correspond to the handle, the rod and the end or tip, such that the handle, not present in all catheters, is a piece of small dimensions that allows the catheter to be handled with ease and, for those that possess it, the cannula from the seminal container to be attached to the catheter.
The rod or body of the catheter is a tube approximately 50 centimetres long that acts as a conduct for the seminal liquid. The diameter of this tube is variable, although its outer diameter never exceeds 10 millimetres.
The point, as the main element of the catheter, is a piece of variable size and form which in any case allows the introduction and attachment to the neck of the uterus. They can take on cylindrical form (lid), made of foam and of a size near to 2 centimetres, and they can be conical, made of different types of plastic and with very variable sizes but which are usually between 3 and 8 centimetres. Attachment to the neck of the uterus is facilitated in some cases thanks to the helical form of the cone and in other cases thanks to the existence of rings or supplementary laminas that increase the degree of coupling between the catheter and the irregularities of the cervical wall.
In the French patent FR 8419723 a solution for a catheter is described, in which the terminal cannula does not emerge axially from the tip of the catheter, but rather does so laterally, such that said cannula, because of its inclined arrangement, impinges the wall of the uterine neck, which may produce scratching, and also makes handling difficult and uncomfortable.
In addition, in this Patent FR 8419723, it is specified that the cannula should have at least one lateral aperture, which suggests that the number of outlets is not determinant or important, inasmuch as in said Patent, the only thing that is foreseen is that the semen is introduced into the uterine neck, but with any orientation of outlet or outlets.
The artificial insemination device that is put forward is characterised in that inside the catheter a cannula is placed axially through which it is possible to achieve a post-cervical insemination, by lengthening the length of the insemination conduct beyond the uterine neck, depositing the semen in the uterine horns.
The new artificial insemination device consists of a standard catheter consisting of a tube or rod of flexible material and of a certain length, that has at its front end a standard tip, preferably cylindrical, with a widening spiral for attachment to the uterine neck. The back end of the catheter has a handle or a widening suitable for handling. The elements of the new invention consist of a hollow cannula suitable for post-cervical insemination. For this, the cannula is hollow, preferably of cylindrical form, whose outer diameter is particularly suitable to be introduced and housed, fitting tightly but allowing movement, inside the catheter. The cannula is obviously longer than the catheter, and is equipped at its rear end with a coupling device to allow bottles or tubes containing the semen to be introduced or the containers that contain it, directly if it is possible or with an intermediate adaptor. The front end of the cannula finishes in sphere or solid bead which closes it. A few centimetres from this sphere, the cannula""s cross-section narrows gently, with two laterally opposite orifices to be found in said narrowing for expulsion of the semen.
In its use and functionality, in addition to the trans-cervical cannula, the insemination catheter requires a gynaecological lubricant, the way to proceed being as follows:
The vulva of the pig is cleaned carefully and the catheter is prepared to be introduced. Sufficient quantity of gynaecological gel should be applied to the tip of the catheter on the outside and inside of the outlet. Next, it is placed in position conventionally until the tip of the catheter is fixed to the uterine neck, attached to the first 3 or 4 centimetres, as is the case in traditional artificial insemination. Next, the trans-cervical cannula is introduced through the rear end of the catheter until coming into contact with the cervical rings. During this operation, the cannula impulses the gynaecological gel towards the inside of the neck of the uterus, activating the terminal ball of piston or plunger. This action is very important as, in this way, the gynaecological gel is deposited deep in the neck of the uterus to subsequently facilitate the advance of the cannula along its length to the body of the uterus. This is necessary as, in this fashion, as the cannula continues to be propelled through the catheter it ends up emerging on the outlet of the tip. Once the cannula emerges through the point of the catheter, the cannula is still pushed. The front end of the cannula, which has emerged through the point of the catheter, passes through the cervical rings until reaching the neck of the uterus. This advance of the front end of the cannula through the uterine neck is facilitated by the existence of the gynaecological gel previously impelled and the rounded form of the end of the cannula, thus avoiding possible damage or erosions in the mucus of the uterine neck. This additional distance advanced by the end of the cannula makes a better fertilisation possible. Next, the container with the seminal material is placed over the rear outlet of the cannula and the insemination performed. Once the seminal dose has been applied, the cannula is partially retracted. The set of the cannula and the catheter are then removed in conventional fashion.
The new invention confers important advantages, as it allows trans-cervical insemination with the semen deposited directly into the body of the uterus, instead of in the start of the uterine neck, as occurs conventionally, which requires that the sperm travel approximately 10 to 15 centimetres naturally until reaching the uterine body. The second advantageous point is the use made of the semen employed, as in the traditional procedure part of the semen deposited in the cervix may turn back, and be discharged from the vagina and therefore not used. According to the invention, the dose of semen to be used can be reduced, achieving an equally satisfactory use, with better yield of the sperm and genetic material used from the breeding male pigs.
The trans-cervical cannula is suitable for use in conjunction with any standard catheter or catheter already in existence, provided it has sufficient diameter and length in accordance with the needs, with the indispensable requirement that the tip of the catheter is opened frontally, in order that the cannula may emerge easily.
In an alternative form of embodiment, the lid of the cannula, instead of adopting a spherical configuration, adopts a lengthened configuration with a rounded end, with a perimeter groove and means in which the outlet orifices are precisely established, in twos and diametrically opposed. Said cannula, which will measure not less than 60 centimetres and not more than 75 centimetres, has in its end flow a connector by which the fastening connector will be attached to the seminal container.
In accordance with another of the characteristics of the invention, the rear end of said lid, basically of the screw type, is of larger diameter than the cannula to which it is attached, in order to totally cover the edge corresponding to the border or end of the latter, thus avoiding lesions due to friction with the uterine wall of the pig.
In accordance with another of the characteristics of the invention, it has been foreseen that said lid has specifically two outlet orifices, diametrically opposed to one another and which complementarily the connector or the cannula itself, for its entirety or part of its length, incorporates a signal that allows said orifices to be duly aligned in the uterus of the pig, specifically to bring them face to face with the respective uterine horns, which allows a considerable reduction in the seminal dose necessary to obtain satisfactory results from the insemination.
On the other hand, and from the point of view of maintaining the device sterile during the manipulation thereof, it has been foreseen that it is marketed in such a fashion that the front end of the cannula and thus also the end lid, are housed inside the helical tip, in order to keep them perfectly protected and so it is not necessary to perform any manipulation on them to thread the cannula through the inside of the tube or catheter.
To ensure that it is positioned in a stable fashion, it has in turn been foreseen that said tip has its front end closed, in order to avoid the accidental emergence of the cannula, and affected by at least one diametric cut to all its deformation and corresponding opening on applying axial pressure of an appropriate magnitude on the cannula.
This implies a greater emergence of the cannula at its other, rear, end; having anticipated for this and to make packaging easier, that said cannula can be fragmented into two sectors, that can be duly coupled at the moment of use of the equipment, one of them equipped to this effect with an inner casing coupled by pressure thereon and emerging to be coupled in analogous fashion to the other sector, with a suitable pressure to prevent accidental rotation of a sector with respect to the other from occurring and, as a result, the loss of marking for orientation of the front lid.
In this sense, it is also foreseen that either the two sectors of the cannula are related through a markedly Inclined plane that determines a single position relative to each other, which in substitution are related by an angular cut, with the same end, or by any other means that allows the relative position between the two sectors to be maintained.